Metal clamp



April 6, 1943. i F. A. KELLOGG METAL CLAMP Filed June 18, 1941 PatentediApr. 6, 194,3l p i s V'PA'TE I METAL om Frank A.` Keilogg, Aurora, Ill. Application June is, 1941,- se'riai No. 398,670 1 claim. '(cl. iii-som:

` The present linvention relates to clampsffor holding metalflwork during machining operations and aims generally'to'improve existing clamps for that purpose.,l v

One of the primary objects of the invention is i dn the bearing ll of the frame. The threads 26.- A

vof the sleeve are engaged by theend of a pawl the provision of an improved clamp which'may' i 1 .be quickly operated'to engage and disengage the work.

i A further object er the mve'nnon is the provision of an improved clamp rof the type referred.

to wherein one of the clamping plates is spring i tensioned and is associated with a threaded adjusting means and the other clamping member is cam actuated for quick manipulation to engage and release the work.v v i Other objects and advantages of the invention will be apparent topersons skilled in the art .'upon reference to the accompanying drawing illustrating a preferred embodiment of the inveni tion. i i

Inthedrawing p, Fig. 1 is a side elevation of the olamp in open i i or reieasedposition. i

Fig. 2 is a similarview of the clamp in closed or clamped position; and

, mg. a is en emsrged man sections view taken on the line 2-3 of Fig. 1.

In the embodiment of theinvention illustrated in the drawing, the improved clamp comprises a U-shaped frame Ill formed at opposite ends with tubular bearings ll and l2,` one end being fluras illustrated mrig'; 1, and adjustabiyjmountea 28l mounted'on a pin 29y on the Voutside of the bearing, the engaging` end extending through I opening 30 into engagement with the threads 26.

The pawl 28 is normally tensionedfbyr springl 3l`, to position the engaging end in engagement with J the sleeve between' adjacen'tlthreads.

first releasing the pawl 28 from engagement With the threads 26 and merely sliding the member 25 i in the bearing. The member 25 should be so posltioned in the bearing that the spring 22 is tightly compressed with its convolutions in con- `-tact with` each other while the ciamp is closed.

To effect thisadjustment the member 25 may be' rotated in .the sleeve as by hand wheel`32 which causs a iongitudinal feed of the member- 25 in the sleeve because the pawl 28 acts as a nutin engagementwith the threads v26. v

The length of movement of the clamping mem- `ber I'I is preferably slightly in excess `of the length of movement of the member 20 in the ref taining member 25, which with the proper ad- Justment of the member 25 in thesleeve-'ll insures complete compression of the spring 22 and v ther provided with a bifurcated portion providing a pair of spaced ears I! between which isoperating cam lever mounted on a pin IS.

The lever il is formed with a cam portion IG engaging a movable clamping member Il slidable in bearings l2 and tensioned'against the cam by spring il. 4

The opposite clamping member preferably comprises a screw operated clamping rod comprising a head 2l normally tensioned inwardly -by a spring 22 surrounding the rod 2l and positioned between washers 24, which washersar'e located one adjacent and below the head .2i`

and the other atan end of an adjustable retaining member 25. v

-The` adjustable retaining member 25 preferably comprises an elongated tubular screw having external threads 26.V preferably square threads, and a smooth bore 21, to receive spring urged rod 20, the length of said rod being and the depth of said bore being sufllcient to prevent the eiecv tion of said rod by the expanslon od'theispringv rigid clamping of the workpiece W. Similarly when the clamp ls releasedfthememb'er ll reltracts a greater distance than member 21)v is extended by the spring,l facilitating quick removal ofthe'work.l I v Obviouslytheinv'ention is not restricted tothe i details of constructionshown and describedbut 'includes as well equivalent constructions as within the scope of I' claim:

the appended'claim. k A vworkclamp comprising a U-s haped `.frune `formed'yvith a clampv means at one end` and a`- bearing at its'other end, a clamping member journailedin said bearing, saidclampingmember comprising an extemally threaded long hollow sleeve, a headed long rod slidably mounted in said sleeve and a coil spring surrounding said rod and 'interposed between the head on said rod and' said sleeve, and reieasable means in said bearing for engagement with-the thread of said hol-` low sleeve for effecting longitudinal adiustment of the sleeve in the bearinguponrotation'of the sleeve. H f

In using the clamp, the retaining. member 25 may be adjusted manually in the bearing il by I i fan`` FRANK aKELLoGG. I 

